Electric space-charge device



Nov. 23, 1948.. H. SMITH 2,454,757

' ELECTRIC SPACE CHARGE DEVICE Filed Opt. 1Q 1945 2 Sheets-Sheet 1 FIG.1

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L. H. SMITH ELECTRIC SPACE CHARGE DEVICE Nov. 23, .194;&

2 Sheets-Sheet 2 Filed 001;, 1, 1943 FIG.4

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FIG.5

INVENTOR.

Patented Nov. 23, 1948 mural) STATES PATENT OFFICE LesterH. Smith,Maplewood, N. J. Application October 1, 1943, Serial No. 504,531

I 1 This invention relates vices for creating an electric space chargewithin a volume of gas or vapor or within a suspension of liquid orsolid particlesin a gas. In particular this invention is concerned withthe use of high frequency fields for increasing the .eifect oisuchelectric space charges on thegases or suspended materials beingprocessed.

to improvements in de- The improvements proposedare particularlyconcerned with themethods of mechanically pro jecting electricallycharged physical particles from'emittingjelectrodes such as have beendescribed in my copending applications No. 481,767 and No. 504,532both-now abandoned, and the combination of high frequency electrostaticand electromagnetic fields with the space charges so produced, I Q I 1-Considerable experimental work has been done in the treatment of variousgases with high frequency electrostatic and electromagnetic fieldsnchanicallyfprojected from the emitting electrode,

aswell as increased ionization' and local electrolytic actionthroughout. the gas or the suspension in agas. Other objects of thisinvention will be apparent from the drawings and the followingdescription of the features of the invention and in themevision ofapparatus and methods c of operation for accomplishing the foregoingobject.

In accordance withone modification of my invention, electricallychargedphysical particles are mechanically projected from an emitting.electrodewhich may be a nozzle, a vibratory plate, or a rotatingsurface. Necessary electrostatic fields toinduce' the'fiow of electriccharges on the i projected particles are set up by a wide spaced gridelectrode in close proximity to .the emitting electrode and a collectingelectrode located at a proper distance from the emitting electrode andmaintained at such a direct current potential as 1 to cause a drift ofthe charged particles toward the collecting electrode which alsoprovides an external electrical return circuit to the emittingelectrode. At thesame time al fiow'. of gas or of a gas containing asuspension isrnaintained through i Claims. (Cl. 204-312) tentials, ahigh frequency potential source is connected between the emittingelectrode or grid electrode and the collecting electrode, using thesesame electrodes to produce a high frequency electrostatic field. Thedesign of the electrodes, the path of the drifting space charge and thecirculation of the gas or suspension in a. gas are such as toobtain'maximum processing effect.

In accordance with a second modification of my invention, electrodes forproducing a high frequency electrostatic field which are separate fromthe electrodes used to produce the direct current electrostatic fieldsare used. This will be made clear in the discussion of the drawings. Inaccordance with a third modification of my invention, a space charge isproduced in the same manner as described in connection with the firstmodification by the projecting of electrically charged physicalparticles from an emittingelectrode in combination with a grid electrodeand a collecting electrode. This space charge is passed through or inclose proximity to a high frequency winding which generates a, highfrequency magnetic field. At the same time a flow of gas or of a gascontaining a. suspension is maintained through the same path traveled bythe drifting space charge. I

The circulation of the gas or suspension tolbe processed shouldpreferably be parallel to the path of the space charge between theemitting and collecting electrodes. It may be counter-current withproper proportioning of direct current potentials and gas velocities.

It'may be desirable to have the electrically charged physical particlesprojected from the emitting electrode, consumed or evaporated uponmixing with the gas or suspension to be processed, leaving the electricspace charge available in a free state throughout the gas or suspension.

Throughout this specification and the accompanying claims I have usedthe expression-wide spaced or intermediate gridto describe one of theelectrodes involved in this invention. By this expression I mean anyarrangement of Wires, rods or plates which in combination with anemitting electrode and a collecting electrode may be used to produceunobstructed electrostatic flux lines directed from the emittingelectrode toward the collecting electrode. Obviously, the wires orplates must have open spaces between them. For purpose of illustration,I have shown in the drawings wide spaced mesh grids constructedoiparallel wires orplates. I

Referring to the drawings,

Fig. 1 illustrates a, preferred form of space charge device in which thesame electrodes are used for setting up both the direct currentelectrostatic fields and the high frequency electrostatic fields.

Fig. 2 shows a modification of Fig. l in which the entering gas to beprocessed passes through the emitting electrode. Furthermore, separateelectrodes are provided for setting up the high frequency electrostaticfield.

In Fig. 3 is shown a. preferred form of space charge device in which thedrifting space charge and the gas or suspension circulating through thethe device of Fig. 3.

cycles per second is connected to a primary coupling coil 2I. Asecondary winding 22 coupled with coil 2I introduces a. high frequencypotential in series between collecting electrode I3 and direct currentpotential source I8.

Operation of the device shown in Fig. l is as follows: a gas to beprocessed, such as propane, for example, enters through raw gas inlet 2,passes downward through collecting screen electrode I3 and leavesthrough processed gas outlet 3. The emitting electrode 5 projects acloud of liquid particles, of liquid butane, for example, downwardduring periods of vertical vibration. These liquid butane particlescarry an electric charge .due to. the direct current potentials of gridelectrode I2 and collecting electrode I3. After passing "downwardthrough the wide spaced grid In Fig. 5 is illustrated an alternativearrange I ment of the high frequency electromagnetic winding of Fig. 3.7 I t Figure 6 shows a form of rotating emitting electrode which can beutilized in either Fig. 1 or Fig. 3 in place of the vibratory emittingelectrodes shown.

In Fig. l; the vessel I is constructed of a non conducting material suchas glass sectioiis'or impregnated wood. The vessel I is provided with araw gas inlet 2 and processed gas outlet" 3 and drain outlet I. Aflexible circular plate electrode 5 in the upper portion of vessel l issupported from insulating collar 23 and is connected to the lower end ofthe shaft 6 which is in turn connected to -a source "I of intermittentvertical-vibratory motion of approximately 120 cycles per" second. Theplate electrode 5 is the emitting electrode and is supplied with a fluidused to form charged particles through the tube 8. The'tube'il passesdownward through the top of vessel I and makes a right angle bend andruns horizontally close" bration of emitting plate 5, additional'fluidis sup- F? plied through tube 8 and slots 9 and I0 and runs downhill onthe lower surface of plate electrode 5 covering the lower surface ofplate electrode 5 with a thin film of liquid. This thin film is.projected downward in the form of tiny droplets upon vibration of theplate electrode 5." .A gas. tight sleeve I I in the top of vessel Ipermits verticalniotion of the shaft 6. A wide spaced grid electrode I2which is located close to the lower surface of emitting electrode 5 isprovided,'a'lso' a-collecting' electrode I3 in the form of a screenCollecting electrode I3 is supported by an insulator I l and insulatingbushing I5 which provides an external electrical connection to electrodeI3. An external electrical connection to grid electrode I2 is providedthrough insulating bushing I6; .The emitting electrode 5 is connected toground, as shown. The wide spaced grid electrode I2 is maintained at a.direct current potential of around 800 volts relative to ground by meansof potential source I 'i. The collecting electrode I3 is maintained at adirect current'potential of around 1500 volts relative to grid electrodeI2 by means of electric charges between emitting electrode 5 and:collecting electrode I3. Resistance 30 is for current limiting purposesin case of temporary'liq- .uid bridges grounding the'electrod'e I2." Asource of high frequency currentat about 50,000

electrode I2, the charged butane particles mix withthe propane gasentering through inlet connection 2. At the same time the electriccharges carried on the particles are subjected to the high frequencyelectrostatic field set up between grid I; and collecting electrode I3.Ionization and inter electrolytic action take place throughout thecirculating gas. Polymerization products result- 'ing may be collectedas condensate in the bottom of vessel I or they may be separated fromthe processed gas bymeans that do not form a part of this invention.Between periods of vibration of the emitting electrode '5, the lowersurface of dis rewet with fluid fed through the tube 8. Residualelectric charges are collectedby electrode I3 and returned through theexternal ciruit to emitting electrode 5.

In'Fig." 2, the vessel I is also constructed of electrically"nonconducting material as in Fig.

-l of intermittent vibratory motion. The emitting electrode 5- isacircular flexible plate provided with perforations and is rigidlysupported at the edges by the solid insulating collar 23. Theemitti'ngelectrode 5 is [supplied with fluid used to form charged particlesthrough the tube, 8 which-makes a right angle {bend and extends"horizontally across the top of emitting electrode 5. Aslot' 9' isprovided in the horizontal portion of tube 8 close toth'e surface ofemitting electrode 5. In between periods of vibration of electrode 5 thefluid supplied through tubes and slot 9 runs. down over the frontsurface of emitting electrode 5. The wide spaced grid electrode I2 andcollecting screen electrode I3 are similar to "those in Fig. Landfunction in the same manner except that'they do not set up any highfrequency electrostatic field. The parallel plate electrodes 29 and Z5..are connected through insulating bushings '26 and 21 to the highfrequency secondary windingjlz. The source 20' of high frequency.current and primary winding 2I are the same asin Fig. 1. The emittingelectrode 5 lis connected'to ground. Direct current potentials' IT and I8 andlelectric'al condenser I9 and resistance 36 arethe same as inFig. 1. The high frequency electrodes 24 and 25 are maintained ata'negative direct current potential of about volts relative to ground bypotential source 39. I

" Operation of' thefdevice shownin Fig. 2 is very "similar toft'hat .ofFig.. 1. The gas or suspension of' rnaterial jin agasto be processedenters throughinlet 2;"pas'se's through the perforations in emittingelectrode 5 toward the grid electrode l2 and collecting screen.electrode l3 and out through the processed gas outlet 3. At the sametime, charged particles 'of"the fluid supplied through tube 8 areprojected from emitting electrode 5 through widespaced grid electrode I2and toward the collecting screen electrode l3. Circulating currents andelectrolytic action in the mixture of charged particles and gas or thesuspension to be processed is promoted by the high frequencyelectrostatic fields set up between electrodes 24 and 25.

In Fig. 3 the vessel l is constructed. of electrically non conductingmaterial as in Figures 1 and 2. Likewise, a raw gas inlet 2, processedgas outlet 3 and drain outlet 4 are provided. The arrangement of theemitting electrode 5, methods for supplying fluid to electrode 5 fromwhich charged particles are to be formed and for vibrating the emittingelectrode are identical with those used in Fig. l. The wide spaced gridelectrode I2 is also identical with that of Fig. 1 and serves the samepurpose. In order to have the high frequency winding 28 at a properdistance from the emitting electrode and to avoid excessive circulatingcurrents in the emitting electrode, it is necessary to make use ofseveral intermediate grid electrodes 29 and 30. These intermediate gridelectrodes as well as the collecting screen electrode 13 are shaped asshown in Fig. 4 so as to discourage circulating currents. The direct'current potentials 3|, 32 and 33 which are used between the various gridelectrodes and the collecting screenelectrode l3 are dependent upon thedimensions of the apparatus and gas velocities through the device. Thehigh frequency winding 28 passes completely around the vessel I, asshown, and is supplied with high frequency cur-'- rent from the source20 at a frequency of about 50,000 cycles per second. Items l5, l6, 3'!and 3,8 are insulating bushings.

Operation of the device shown in Fig. 3 isas follows: The gas to beprocessed, such as propane, for example, enters through the raw gasinlet 2 and mixes with the electrically charged particles, ofliquidbutane, for example, which are pro- J'ected downward from thelower surface of electrode 5, as in Fig. 1. The mixture of chargedbutane particles and propane as travels downward through theintermediate grid electrodes 1' 29 and 30. As this mixturepasses throughthe high frequency electromagnetic field set up by the windin 28,circulating currents are produced throughout the mixture, resulting inincre aed ionization of the gas or suspension and local electrolyticaction. Residual electric charges equal to those leaving the emittingelectrode 5 are collected on the screen electrode I3 and are returnedthrough the external circuit shown to the emitting electrode 5LPolymerization products resulting may be collected in the bottom ofvessel l-or may be separated from the processed gas leaving throughoutlet 3 by a separate condenser not shown. c

The alternative arrangement shown in Fig; 5 of the high frequencywinding used in Fig. 3 consists merely'of directing the electromagneticfield across the path of the charged particles and gas by splitting thewinding into two halves 34 and 35. Other parts of the device remain thesame as in Fig. 3.

In Fig. 6 is shown an alternative arrangement with a rotating emittingelectrode which can be used in place of the vibratory emittingelectrodes shown in Figures 1 and 3. A partial section only is shown inwhich item l is the wall of the vessel, H is a gas tight insulatingbushing which allows rotation of a shaft 6 and a disc emitting electrode5.' Item 40 is a motor which turns shaft 6 at approximately 200 R. P. M.Tube 8 feeds fluid material to the top surface of disc 5 which materialis projected in the form of fine particles from the edge of disc 5 andfalls through the openings in the wide spaced or intermediate gridelectrode 12. Item 15 is an insulating bushing.-

In Figures 1 and 3, I have shown electrical connections for creatingspace charges of negative polarity. Reverse connections of the potentialsources used will create positive space charges just as readily asnegative ones. Also, the size of the potentials applied between thevarious electrodes and the rate of vibration or rotation of certainemitting electrodes are not criticalbut can be varied as desired.

Withregard to the electrical processing of suepensions ingases, it iscontemplated that certain materials in a finely divided state may besuspended in a gas in order to be able to process them in this manner.The gas present may or may not enter into the reaction or change ofstate which it is desired to accomplish.

As mentioned in my copending applications it may be desirable to useinsulating bushings and supports which are provided with internalheating coils so as to prevent wetting of the insulating surfacesexposed inside of the processing chamber.

Itis to be understood that wherethe term gaseous material is used in theappended claims, the term is to be construedas covering gaseousmaterial, and gaseous material having liquid or solid particlessuspended therein.

This invention has been illustrated only in a general preferred formthroughout-and it should be'understood that it is capable of many andvaried modifications without departing from its purpose and scope, and Itherefore believe myself to be entitled to make and use any and all ofthese modifications such as suggest themselves to those skilled in theart to which the invention is directed, provided that such modificationsfall fairly within the purpose and scope of the hereinafter appendedclaims.

c What is claimed is:

l. Gaseous phase electric space charge device comprising a perforatedemitting electrode, means associated with said emitting electrode formechanically projecting a stream of physical particles from the surfaceof said emitting electrode, a collecting electrode and anintermediategrid electrode provided with an opening for the passage ofcharged physical particles from said emitting electrode through saidintermediate grid electrode to said collecting electrode, means formaintaining a rising potential gradient between the respectiveelectrodes causing a drift of electrically charged physical particlesfrom said emitting electrode to said collecting electrode,

, means for setting up a high frequency field with.-

in said electric space charge device and means for circulating gaseousmaterial to be processed through the perforations in said emitting elec-'trode and through said electric space charge device.

2. Gaseous phase electric space charge device comprising an emittingelectrode, means asso ciated with said emitting electrode for projectingmechanically a stream of physical particles from the surface of saidemitting electrode, an intermediate grid electrode formed to provide aPath for physical particles projected from said emitting electrode,means for maintaining said intermediate. grid electrode. at such anelectrical potential; relative to said emitting electrode that certainof the particles leaving the. surface of said emitting electrode carryan electric charge and retain this charg in passing through saidintermediate gridelectrode, a collecting electrode and means formaintaining said collecting electrode at such an electrical potentialrelative to said emitting electrode and said intermediate grid electrodeas to cause a. drift of electrically charged particles toward saidcollecting electrode, said electric space charge device also comprisingmeans for setting up a high frequency of the particles leaving thesurface of said, emittin electrode carry an electric charge and retainthis charge in passing through said intermediate grid electrode, acollecting electrode; and means for maintaining said collectingelectrode at such an electrical potential relative to. said emittingelectrode and said intermediate grid electrode as to cause a drifc ofelectrically charged particles toward said collecting electrode, saidelectric space charge device also comprising means for increasingcirculatin currents originating in said electrically charged particlesby the use of high frequency fields and means for introducing gaseousmaterial to be processed into and for withdrawing processed materialfrom said device.

4. Gaseous phase electric space charge device comprising a rotatingelectrode, means. associated with said rotating electrode for.proiecting mechanically a stream of physical particles from the surfaceof said rotating electrode, an intermediate grid electrode formed toprovide. a path for physical particles projected from said rotatingelectrode, means for maintaining said intermediate grid electrode atvsuch an, electrical potential relative to said rotating electrode thatcertain of the particles. leaving the surface of said rotating electrodecarry an electric charge and retain this charge in passing through saidintermediate grid electrode, a collecting electrode and means formaintaining said collecting electrode at such an electrical potentialrelative to said emitting electrode and said intermediate grid electrodeas to cause a drift of electrically charged particles toward saidcollecting electrode, said electric space charge device also comprisingmeans for setting up a high frequency field within said electric spacecharge device and means for introducing gaseous material to be processedinto and for withdrawing processed material from said device.

5. An apparatusv for effecting gaseous: phase chemical reactionscom-prising an emitting, electrode, means associated, with said emittingelec trode for projecting mechanically a stream; of physical particlesfrom. the surface of said emitting electrode, an' intermediate gridelectrode formed to provide; a path for physical particles projectedfrom said emitting electrode, means; for maintaining said intermediategrid electrode at such an electrical potential relative to said emittingelectrode that certain of the particles leaving the surface of saidemitting electrode carry an electric charge and retain this charge inpassing through said intermediate grid electrode, a. collectingelectrode and means for maintaining said collecting electrode at such anelectrical potential relative to said emitting electrode and saidintermediate grid electrode as to cause a drift of electrically chargedparticles toward said collecting electrode, said apparatus alsocomprising means for setting up a high frequency field within saidapparatus and means for introducing gaseous material to. be processedinto and for withdrawing processed material from. said apparatus.

6. Gaseous phase electric space discharge device com-prising: anemitting electrode, means Operatively associated with said emittingelectrode for vibrating at least a portion thereof to mechani-callyproject a stream of physical particles from the surface of said emittingelectrode, a, collecting electrode and an, intermediate electrode, saidintermediate electrode being provided with an opening for the passage ofcharged physical particles from said emitting electrode, through saidintermediate grid electrode to said collecting electrode, means formaintaining a rising: potential gradient between. the respectiveelectrodes causing a drift of electrically charged, physical particlesfrom said, emitting electrode to said collectin electrode, means forsetting up. a high frequency field within said electric space chargedevice and means for introducing gaseous. material to be processed intoand for withdrawing processed material from said device.

LESTER H. SMITH..

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 965,060 Babcock July 19, 19101,035,684 Bunet Aug. 13, 19.12 1,440,775 Eddy Jan. 2, 1923 1,809,115Goddard June 9, 1931 2,064,260 Herrmann Dec. 1'5,v 1.936 2,240,914Schutze May 6, i941 2,272,374 Kallmann Feb. 10,. 1 .942 2,285,622.Slepian June 9,1942 2,334,377 Bennett Nov. 16., '1943 FOREIGN PATENTSNumber Country Date 421,811 Great Britain Dec. 20, 193.4 502,063 GreatBritain Mar. 10, 193.9

